component
SMF4729A
Public Made by Adomby adom
Changjing Zener Diodes, SOD-123FL. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownSMF4729A
Changjing · Zener Diodes · SOD-123FL
SMF4729A from Changjing, in a SOD-123FL. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | K | passive | Cathode, marked by the cathode bar on the package; zener voltage VZ for SMF4729A is 3.42V min / 3.47V max per the table at IZT=69mA (nominal 3.3V). |
| 2 | A | passive | Anode; forward voltage VF is max 1.5V at IF=200mA. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Changjing |
| Package | SOD-123FL |
| Category | Diodes |
| Pins | 2 |
Electrical characteristics
Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).
| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Zener voltage (min/max) | VZ | 3.42 | 3.6 | 3.78 | V | @IZT = 69 mA | 2 |
| Zener voltage tolerance | -5 | 5 | % | standard tolerance on nominal zener voltage | 2 | ||
| Test current | IZT | 69 | mA | 2 | |||
| Maximum Zener impedance | ZZT | 10 | Ω | @IZT | 2 | ||
| Maximum Zener impedance (knee) | ZZK | 400 | Ω | @IZK = 1 mA | 2 | ||
| Reverse leakage current | IR | 100 | uA | @VR = 1 V | 2 | ||
| Maximum DC Zener current | IZM | 251 | mA | 2 | |||
| Maximum surge current | IRM | 1255 | mApk | non-repetitive 8.3ms pulse width square wave or equivalent sine-wave | 2 | ||
| Forward voltage | VF | 1.5 | V | IF=200mA | 1 | ||
| Thermal resistance junction to ambient | RθJA | 170 | ℃/W | Between junction to ambient | 1 | ||
| Thermal resistance junction to lead | RθJL | 26 | ℃/W | Between junction to lead | 1 | ||
| Power dissipation | Pd | 1 | W | TL=75℃ | 1 | ||
| Operation junction and storage temperature range | TJ,Tstg | -55 | 150 | ℃ | 1 |
CAD (KiCad official)
- Symbol:
SMF4729A - Footprint:
Diode_SMD:D_SOD-123F - 3D model: SOD-123FL (KiCad packages3D, STEP)
- 3D model files:
smf4729a-etched.step/smf4729a-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);smf4729a.step/smf4729a.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Changjing datasheet (5 pp, sha256
8f6e4acc3701b115, retrieved 2026-10-22, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-sonnet-5-5(text), consensusclaude-sonnet-5-5(agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish. - CAD: KiCad official libraries (CC-BY-SA 4.0).